NEW YORK (Reuters Health) - Mental disorders including depression and alcohol abuse were linked to a higher risk of suicide among current and former military personnel, in a new study - but combat exposure and number of deployments were not.

Researchers said the analysis of 83 suicides between 2001 and 2008 does not support the assumption that experiences in combat - such as seeing dead bodies or firing a gun - and time spent in a war zone are directly tied to a higher suicide risk.

"It was suspected of course that the stresses of combat exposure would lead to bad outcomes such as suicide," said Dr. Edward Boyko, from the Veterans Affairs Puget Sound Health Care System in Seattle, who worked on the study.

"We suspected that there would be an association between combat and suicide, given that there's been a reported increase in suicide rates," he told Reuters Health.

The report included 151,560 veterans and current military personnel who were assessed in three waves starting in 2001.

Every three years study participants filled out a survey that asked about experiences in combat and included assessments for depression, manic-depressive disorder and alcohol abuse and misuse.

Researchers led by Cynthia LeardMann from the Naval Health Research Center in San Diego used Department of Defense personnel files to determine how many times and for how long each person was deployed.

Through 2008, 646 of the study participants had died, including 83 by suicide.

The researchers found no difference in the risk of suicide among military personnel who had and had not been deployed to Iraq or Afghanistan, nor were more cumulative days deployed tied to a higher suicide risk.

Suicides were equally common among study participants of different military ranks, service branches and occupations.

However, male service members were twice as likely to commit suicide as women, the study team wrote Tuesday in the Journal of the American Medical Association.

When deployment history and gender were taken into account, depression was tied to a doubling of the risk of suicide, manic-depressive disorder to a four-fold risk and alcohol-related problems to almost three times the risk of suicide.

For example, five out of 1,227 people - or 0.4 percent - whose assessments showed they were manic-depressive committed suicide, compared to 76 out of 146,403 - less than 0.1 percent - without manic-depressive disorder.

"I don't think (the results) are surprising, in the broader sense," said Michael Anestis, a clinical psychologist from the University of Southern Mississippi in Hattiesburg, who has studied suicide in the military.

"They're saying that the risk factors in soldiers are not that dissimilar to the risk factors in civilians," Anestis, who wasn't involved in the new research, told Reuters Health.

He said the findings don't mean experiencing combat doesn't have any harmful long-term effects on military personnel - just that how people deal with combat mentally, and their situation and stress level at home, may also be important.

LeardMann said mental health prior to ever seeing combat was the main driver for later suicide risk.

"While it's possible that some of these behaviors are happening after deployment, most of our findings ... are from people who are completing these surveys prior to their first deployment," she told Reuters Health.

Past studies have shown an increase in the number of active duty service people with mental disorders since the mid-2000s, according to the researchers, possibly due to the stress of being part of a military that has been at war for so long.